This invention relates to antibiotic compositions suitable for pharmaceutical use. More particularly, it relates to aqueous oxytetracycline solutions containing 2-pyrrolidone.
Previous efforts made to prepare compositions suitable for topical or parenteral administration which contain more than 200 mg./ml. have been unsuccessful. This is of particular importance in the case of veterinary oxytetracycline parenteral compositions in which high doses are required.
U.S. Pat. No. 2,980,584 discloses aqueous parenteral solutions of oxytetracycline metal complexes containing 25-80% of an acetic or lactic acid carboxamide, such as N,N-dimethylacetamide and N-(.beta.-hydroxyethyl) lactamide at a pH of 8.5-9.5. Concentrations of 10 to 100 mg./ml. are disclosed.
U.S. Pat. No. 2,990,331 discloses parenteral solutions of oxytetracycline hydrochloride, containing about 50 mg./ml. having a pH value between 5 and 7, containing magnesium ions, an alkali bisulfite and a carboxylic acid amide, such as lactic acidhydroxyethyl amide.
U.S. Pat. No. 3,557,280 discloses aqueous solutions of oxytetracycline containing 1 to 20% oxytetracycline, a magnesium compound and polyvinylpyrrolidone, 7.5 to 25%, at a pH of 8.0 to 9.5.
Belgian Pat. No. 825,656 discloses aqueous solutions of oxytetracycline containing 4 to 11% oxytetracycline, 20 to 30% of a polyethylene glycol, such as polyethylene glycol 400, a magnesium compound and 0.10 to 0.35% of a buffer, such as tris-(hydroxymethyl)-aminomethane at a pH of 8 to 9.
French Pat. Publication No. 2,258,187 discloses aqueous solutions of oxytetracycline containing 50 mg./ml. of oxytetracycline, 5 to 7.49% polyvinylpyrrolidone and up to 24.9% of an acid amide containing one to six carbon atoms, such as dimethylacetamide, at a pH of 8 to 9.5.